Adedayo Olajide Ajayi
Olugbenga Ebenezer Ige
Patience Yakubu

Background: Various forms of microorganisms have developed multiple resistances against the effects of applied antibacterial agents controlling them. Hence, there is a need to formulate potent antimicrobial agents from natural sources to eliminate them from the environment. The aim of this study was to investigate the potency of chitosan conjugated with some medicinal plants against recalcitrant microorganisms and overcome the problem of multiple antibiotic resistance. Methods: In this study, the synergistic effects of chitosan derived from snail shells were explored in conjunction with eight plant sources, including Ocimum gratissimum, Croton zambesicus, Phyllanthus niruri, Aloe barbadensis, Moringa oleifera, Andrographis paniculate, Aloe barbadensis, and Curcuma longa. The investigation focused on the antimicrobial properties of these combinations, aiming at enhancing the efficacy of pharmaceutical products against antibiotic-resistant strains. Four samples were analyzed in this regard. Sample A consisted of ۰.۵ g of sulphur nanoparticles (SNPs) conjugated with chitosan, and Sample B contained ۱ g of SNPs conjugated with chitosan from shrimp shells dissolved in ۱% acetic acid. In addition, Sample C involved chitosan from shrimp shells dissolved in ۱% acetic acid, and Sample D utilized chitosan from snail shells dissolved in ۱% acetic acid. All demonstrated varied antimicrobial potentials. Results: Notably, Sample B, which utilized chitosan from shrimp shells as nanocarriers for SNPs, exhibited significant antimicrobial activity, with zones of inhibition measuring up to ۳۵ mm and ۳۷ mm against multidrug-resistant strains of Staphylococcus sp. (coagulase-negative), Klebsiella oxytoca, and Escherichia coli, respectively. Additionally, promising antimicrobial effects were observed against organisms such as Pseudomonas aeruginosa, Klebsiella ornithinolytica, and E. coli, with zone sizes reaching ۲۰ mm, ۲۳ mm, and ۲۵ mm, respectively. Iron oxide NPs (Fe۳ O۴ ) and silica-coated iron oxide NPs displayed lower activity levels, except at the ۱۰۰ mg/mL concentration, where they represented efficacy against certain multidrug-resistant strains such as AKR ۱۸ - Enterobacter agglomerans, OKI ۱۰ - Acinetobacter haemolyticus, and T۳۰ – K. oxytoca. Conclusion: The findings of this study offer valuable insights into the management of infectious disease and the treatment of challenging pathogens in healthcare systems, providing a potential roadmap for combating antibiotic resistance and improving therapeutic strategies.